Hello there, I recently installed Ubuntu 11.04, and from there used the package manager to download/install the arduino package. I did not download anything else. I then got started on programming my Uno. It worked fine uploading the blink and digitalReadSerial example sketchs, but when I tried to read the Serial data, it said it could not find the serial port. I went to tools, but there were no serial ports listed. I could not upload a new sketch either.
I found I could upload a sketch by holding down the reset button, plugging in the arduino, pressing the upload button, and then releasing the reset when the Rx LED blinks, but that is a major pain.
Summary: Ubuntu 11.04 (installed a few days ago, only downloaded Chromium, Arduino and recommended packages) (dual boot with Windows XP). Arduino Uno, fully working Arduino 0022, installed with Synaptic package manager Can upload when no serial data is sent back, can't find serial port when data is being sent back (on same USB port, same session, etc.) Can upload/etc. on Windows.